Molds for making injected molded parts are typically utilized in relatively high production environments where thousands of parts are molded in quick succession. These molds frequently are in continuous operation for days or weeks making the same part. When it is desirable to make a different part the mold is removed from the mold machine and replaced with a different mold. This, of course, means that the mold machine must be taken out of production while the molds are being changed. This usually does not cause an economic hardship because of the very large numbers of parts that are produced during the relatively long production cycle. The relatively short down time to change the molds is tolerable. However, when shorter production cycles are required because a smaller number of different parts is needed, the production down time needed for changing molds becomes more significant resulting in a greatly increased economic liability.
Reconfigurable molds are known that can be manipulated to mold different parts. These molds usually require that the mold be disassembled and mold sections either be added or subtracted. This, of course, requires that the mold machine be taken out of production while the mold is reconfigured. An example of this type of reconfigurable mold is disclosed in U.S. Pat. No. 5,255,889 which issued Oct. 26, 1993 to Collette et al. The '889 patent discloses a blow mold for making a beverage bottle, having upper and lower mold sections that are joined by various intermediate sections that can be added or removed from the middle to mold the desired size bottle. While some of the same mold parts are common to all parts that are molded, the reconfiguring process consumes a significant amount of time resulting in slowed production. As with most mold machines, after shutdown of the machine to reconfigure the mold, the machine must be purged of old mold material. When the machine is again brought on line, the first several molded parts must be discarded until the process restabilizes. Another example of a reconfigurable mold is disclose in U.S. Pat. No. 4,861,534 which issued Aug. 29, 1989 to Boehm et al. This mold is for molding circuit boards and utilizes a single mold cavity with an array of core pins that are selectively retractable from the cavity. By allowing only the core pins that are required to produce the desired hole pattern in the circuit board to remain in the mold cavity and retracting all others, any desired hole pattern may be produced in the circuit board. However, when a circuit board of different size is required, the mold must be changed.
What is needed is a reconfigurable mold that can be easily and automatically changed to make relatively small quantities of different parts without taking the mold machine out of production for long periods of time while the mold is changed.